Alternate Endings:
There is three possible endings to the game, but it all depends on
your score at the end of the game.
For the Normal ending, your score has to be under 80,000 and the
last number cannot be a zero.
For the Bad ending, your score has to be under 80,000 with the
last number being a zero.
For the Good ending, your score has to be over 80,000 and the last
number being anything.
Bonus Room:
If you manage to get through the entire game without killing any
civilians or letting the zombies kill any civilians, you will be
rewarded with a bonus room, just before the last boss. The room
contains life-ups and bonus points.
Weak Spot for the Final Boss:
The weakest spot on the final boss is his heart. It looks like a
spinning ball in the middle of his chest.